Those who can say yes, oui, or si to all three questions are significantly more likely to avoid cognitive problems late in life than those who speak only two languages, according to Magali Perquin, PhD, of the Public Research Center for Health in Luxembourg, and colleagues.

Moreover, the effect appears to add up -- more languages equal a lower risk of cognitive impairment, Perquin and colleagues reported in a study to be presented at the American Academy of Neurology meeting in Honolulu in April.

"It appears speaking more than two languages has a protective effect on memory in seniors who practice foreign languages over their lifetime or at the time of the study," Perquin said in a statement.

The findings, from a study of 230 people with an average age of 73, fit into the context of a growing body of literature that suggests a so-called "cognitive reserve" -- developed by intellectual activities -- protects against dementia.

Indeed, a similar study from a Canadian group, presented at the annual meeting of the American Association for the Advancement of Science this month, showed that having two languages rather than one appeared to delay the onset of dementia.

The "use it or lose it model of cognitive function" has been gaining popularity for several years, according to Richard Lipton, MD, of Albert Einstein College of Medicine in New York City. With colleagues, Lipton showed in 2003 that such activities as chess, bridge and doing crossword puzzles appeared to protect against Alzheimer's disease.

But he cautioned that there are at least two other possible explanations for such data, including his own findings.

On one hand, he said, it's possible that the intellectual activities themselves are not protective, but that being the sort of person who does crossword puzzles or learns several languages is the key factor.

On the other hand, he said, it may be that the causality is reversed -- that incipient cognitive impairment impairs the ability to perform such activities.

But the study is "fascinating," he added, and "as an optimist, I would like to believe it is completely true."

The so-called MemoVie study in Luxembourg is a longitudinal analysis of cognition and its risk factors in the elderly and one of the aspects of the study is the effect of multilingualism.

Luxembourg, a small country in the heart of western Europe, has three official languages and a large number of people who speak several tongues.

For the analysis, participants in the MemoVie study were classified as having normal cognition, some cognitive impairment, or frank dementia, with the latter being excluded.

All told, 44 participants had cognitive impairment and the remaining 186 were cognitively normal, the researchers reported.

Participants had spoken -- or currently spoke -- two through seven languages; those with only two languages were considered the reference group for a multivariate analysis that adjusted for age and years of education, Perquin and colleagues reported.

Analysis showed that, compared with bilinguals:

Participants who had spoken three languages were significantly more likely to be protected against cognitive impairment.

Those with four languages were even better off.

Those with five or more languages had similar protection.

Perquin noted that more research is needed to confirm the findings and to see if protection is limited to thinking skills related to language "or if it also extends beyond that and benefits other areas of cognition."